Millers boss Steve Evans brought Milsom and fellow midfielder Michael Tidser to the New York Stadium during the summer from Aberdeen and Morton respectively and missed out to Sheffield United in his bid to sign striker Lyle Taylor from Falkirk.
"The SPL is a mixed league," Milsom told Press Association Sport. "You have Celtic who are in the Champions League and then teams that can barely stay in the division.
"It's not all negative though, there are some really good players, who I'm sure will get a chance to progress elsewhere.
"It's a good stepping stone for your career if you can go there and do well. I don't have too many negative things to say about it.
"There are some good players that I played against."
- Sports & Recreation
- Sheffield United
- Michael Tidser
- Lyle Taylor